(19)

(11)

EP 2 235 275 A2

(12)

(88) Date of publication A3: 10.12.2009 (43) Date of publication: 06.10.2010 Bulletin 2010/40 (21) Application number: 08866796.9 (22) Date of filing: 18.12.2008

(51) International Patent Classification (IPC):  E04B 1/344(2006.01) (86) International application number: PCT/US2008/087485 (87) International publication number: WO 2009/085985 (09.07.2009 Gazette 2009/28)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR Designated Extension States: AL BA MK RS (30) Priority: 21.12.2007 US 962256 (71) Applicants: Services Pétroliers Schlumberger 75007 Paris (FR) FR  Schlumberger Holdings Limited Tortola (VG) GB NL  Schlumberger Technology B.V. 2514 JG The Hague (NL) BG CZ DE DK GR HU IE IT LT NO PL RO SI SK TR  PRAD Research And Development Limited Road Town, Tortola (VG)

(72) Inventors: GUERRERO, Julio C. Cambridge MA 02138 (US) MUNRO, Logan New York NY 10019 (US) (74) Representative: Ford, Michael Frederick  Schlumberger Cambridge Research Limited High Cross Madingley Road Cambridge CB3 0EL Cambridge CB3 0EL (GB)